Rack mountable computer component power distribution unit and method

ABSTRACT

According to the disclosed embodiments of the invention, there is provided a method of supplying electrical power to a series of upright computer blades mounted side-by-side in a closely spaced configuration, including extending an elongated power distribution unit transversely to the upright blades, and electrically interconnecting the upright blades with a series of electrical connectors arranged side-by-side on one side of the distribution unit. In one embodiment of the invention, a second series of electrical connectors are arranged side-by-side on the opposite side of the body of the power distribution unit.

RELATED APPLICATION

This application claims priority to the following U.S. provisionalapplications: Ser. No. 60/384,996, titled “Rack Mountable ComputerComponent and Method of Making Same”, filed May 31, 2002 abandoned; Ser.No. 60/384,987, titled “Rack Mountable Computer Component Cooling Methodand Device”, filed May 31, 2002 abandoned; Ser. No. 60/384,986, titled“Rack Mountable Computer Component Fan Cooling Arrangement and Method”,filed May 31, 2002 now abandoned, and Ser. No. 60/385,005, titled “RackMountable Computer Component Power Distribution Unit and Method”, filedMay 31, 2002 now abandoned, which are each hereby incorporated byreference in their entirety.

This application relates to the following U.S. non-provisional patentapplications: 10/449,799, titled “Rack Mountable Computer Component andMethod of Making Same,” filed May 28, 2003; 10/448,691, titled “RackMountable Computer Component Cooling Method and Device,” filed May 28,2003; and 10/449,608, titled “Rack Mountable Computer Fan CoolingArrangement and Method;” which are each hereby incorporated by referencein their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a new and improved methodand computer components adapted for rack mounting. It more particularlyrelates to such a method and apparatus for computer components adaptedto be mounted in a compact configuration.

2. Related Art

There have been a variety of different types and kinds of methods andsystems for mounting computer components. For example, reference may bemade to the following United States patents:

U.S. PAT. NO. INVENTOR ISSUE DATE 4,258,967 Boudreau Mar. 31, 10814,879,634 Storrow et al Nov. 7, 1989 4,977,532 Borkowicz et al. Dec. 11,1990 5,010,444 Storrow et al. Apr. 23, 1991 5,216,579 Basara et al. Jun.1, 1993 5,460,441 Hastings et al. Oct. 24, 1995 5,571,256 Good et al.Nov. 5, 1996 5,684,671 Hobbs et al. Nov. 4, 1997 5,877,938 Hobbs et al.Mar. 2, 1999 5,896,273 Varghese et al. Apr. 30, 1994 6,025,989 Ayd etal. Feb. 15, 2000 6,058,025 Ecker et al. May 2, 2000 6,075,698 Hogan etal. Jun. 13, 2000 6,220,456 B1 Jensen et al. Apr. 24, 2001 6,305,556 B1Mayer Oct. 23, 2001 6,315,249 B1 Jensen et al. Nov. 13, 2001 6,325,636B1 Hipp et al. Dec. 4, 2001 Re. 35,915 Hastings et al. Oct. 6, 1998 Des.407,358 Belanger et al. Mar 30, 1999

As a result of having available a large number of different types andkinds of mounting techniques, a standard has been adopted for mountingcomputer components in racks according to a certain modularconfiguration. In this regard, computer components such as computerprocessor units, and the like, are mounted one above the other in acolumn in standard size rack configurations. The standard is referred toas the EIA-310-D Standard, as clarified by the Server Rack Specification(SSI).

The housing for each computer device must have a certain heightdimensions according to the Standard. The height dimension must be amultiple of a standard unit “U”. Thus, there can be computer componentswhich are 1 “U” (standard unit) high or multiples thereof. Thus, therecan also be standard rack mountable computer components which are 1 U, 2U, 3 U, 4 U and so on.

Thus, according to the conventional currently-used standard, racks areprovided for storage of computer components in tightly spaced, denselypacked horizontal dispositions, and each computer component mounted inthe rack is suitably dimensioned in multiples of standard unit U. Theracks are movably mounted on casters or the like so that they can bereadily positioned in, for example, a computer room having a tightlycontrolled air conditioning system to ensure proper cooling of thecomputer equipment.

It is highly desirable to configure the computer components in the rackin a compact and highly dense manner for some applications. Thus, it hasbeen important for many applications to position in the computer room orother assigned space as many computer components as possible.

In order to compactly mount the computer components on the rack in ahigh density manner, they are closely positioned one above the other ina column. The data and power cables are positioned in a back plane areaor space within the rack.

For cooling purposes, various techniques are employed. For example,individual fans have been mounted within the housing of each computercomponent. The interiors of the housing have been exhausted to a fanexhaust plenum chamber often times constructed within the rack at oneside thereof.

Such conventional rack mounted systems have several drawbacks. Theindividual fans mounted in each component are expensive, andtime-consuming to replace in case of malfunctions. Also, the back planespace and fan exhaust plenum chamber are wasted space in that theyoccupy spaces which could otherwise be filled with computer components.

Additionally, in order to assemble the rack mounted system forinstallation at the site, each component must be installed in placewithin the rack, and then the cabling for each unit is routed within therack at its back plane space. Such an operation is time consuming, andtherefore expensive since highly trained personnel are required to dosuch an installation. Furthermore, once installed, in order to replace amalfunctioning computer component, the entire system, or at least asubstantial portion thereof, must be shut down so that themalfunctioning unit can be disassembled, and a replacement unitinstalled and reconnected electrically. This, too, is time consuming andexpensive.

Therefore, it is highly desirable to compactly mount in a highly denseconfiguration computer components in a rack mounted system. However, dueto the cabling requirements for such a large number of computercomponents mounted in a single rack, it is difficult to install thecomponents within the rack due to the cabling requirements and stillhave a very densely packed configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings:

FIG. 1 is a pictorial view of a rack-mounted system showing the front,left side and top thereof, which is constructed in accordance with anembodiment of the present invention;

FIG. 2 is a front elevational view of the rack-mounted system of FIG. 1;

FIG. 3 is a left side elevational view of the rack-mounted system ofFIG. 1;

FIG. 4 is a rear elevational view of the rack-mounted system of FIG. 1;

FIG. 5 is a right side elevational view of the rack-mounted system ofFIG. 1;

FIG. 6 is a pictorial view of the rack-mounted system of FIG. 1, showingthe rear, right side and top thereof;

FIG. 7 is a pictorial view of the housing of the rack-mounted system ofFIG. 1 without various components being mounted for illustrationpurposes;

FIG. 8 is a pictorial view of the housing of FIG. 7 illustrating theprocess of installation of fan/LAN trays;

FIG. 9 is an enlarged scale pictorial view of one embodiment of afan/LAN tray for the rack-mounted system of FIG. 1;

FIG. 10 is a pictorial view of the housing of FIG. 7 with the fan/LANtrays installed;

FIG. 11 is a pictorial view of the housing of FIG. 7 illustrating theprocess of installation of blades;

FIG. 12 is a fragmentary, enlarged scale front elevational view of therack-mounted system of FIG. 1 illustrating the relative positioning ofthe fan/LAN trays and the blades;

FIG. 13 is a diagrammatic, right-side elevational view of therack-mounted system of FIG. 1 illustrating the configuration of theright-side cabling;

FIG. 14 is a bottom fragmentary pictorial view of the rack-mountedsystem of FIG. 1 illustrating the cabling in the front and right portionof the control bay;

FIG. 15 is a diagrammatic, left-side elevational view of therack-mounted system of FIG. 1 illustrating the configuration of theleft-side cabling;

FIG. 16 is a bottom fragmentary pictorial view of the rack-mountedsystem of FIG. 1 illustrating the cabling in the rear and left portionof the control bay;

FIG. 17 is an enlarged scale, fragmentary pictorial view of oneembodiment of a power distribution unit (PDU) for the rack-mountedsystem of FIG. 1;

FIG. 18 is a front elevational view of the PDU shown in FIG. 17;

FIG. 19 is a fragmentary top view of the PDU shown in FIG. 17;

FIG. 20 is a rear elevational view of the PDU shown in FIG. 17;

FIG. 21 is a diagrammatic view of the rack-mounted system of FIG. 1illustrating the flow of air therethrough;

FIG. 22 is a diagrammatic view of another embodiment of a rack-mountedsystem according to the present invention and illustrating the flow ofair therethrough;

FIG. 23 is a diagrammatic view of yet another embodiment of arack-mounted system according to the present invention and illustratingthe flow of air therethrough;

FIG. 24 is a diagrammatic view of still another embodiment of arack-mounted system according to the present invention and illustratingthe flow of air therethrough;

FIG. 25 is an enlarged scale top view of one embodiment of a blade ofthe rack-mounted system of FIG. 1; and

FIG. 26 is a left side elevational view of the blade of FIG. 1.

DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

According to the disclosed embodiments of the invention, there isprovided a method of supplying electrical power to a series of uprightcomputer blades mounted side-by-side in a closely spaced configuration,including extending an elongated power distribution unit transversely tothe upright blades, and electrically interconnecting the upright bladeswith a series of electrical connectors arranged side-by-side on one sideof the distribution unit. In one embodiment of the invention, a secondseries of electrical connectors are arranged side-by-side on theopposite side of the body of the power distribution unit.

According to other embodiments of the invention, each one of thecomputer component blades has a similar cut out portion, and the body ofthe power distribution unit has a complementary cross sectional shapereceived by the cut-away portions of the blades to provide a compactmounting arrangement.

According to at least one of the disclosed embodiments of the presentinvention, there is provided a power distribution unit which enables apair of vertically mounted computer components to be mounted verticallyin close proximity to one another in a back-to-back configuration.Furthermore, the power distribution unit enables the vertical componentsto be conveniently slipped into a rack and engage electrically the powerdistribution unit.

General System Description

Referring now to the drawings, and more particularly to FIGS. 1 through21 and 29 and 30, there is illustrated one embodiment of a rack mountedsystem 10 according to the disclosed embodiments of the presentinvention. The rack mounted system 10 includes a rack housing 12configured generally as a rectangular box having a plurality of verticalbays 14. The embodiment illustrated in the drawings includes threevertically spaced-apart bays 14.

Each bay 14 is divided into a front bay portion 16 and a rear bayportion 18 by an intermediate transversely-extending horizontal divider19. The intermediate divider 19 is most clearly illustrated in FIG. 7.The bays 14 are formed in the rack housing 12 in a vertical manner oneabove the other. In a bottom portion of the rack housing 12, a controlbay 21 is provided to house various controlled components, ashereinafter described in greater detail.

The rack housing 12 further includes a fan/LAN tray slot 23 above eachbay 14. Each fan/LAN tray slot is configured to accommodate a fan/LANtray such as tray 27.

The embodiment illustrated in the drawings provides a control bay 21(FIG. 7) having a bottom opening 25 (FIG. 7) for facilitating air flowto receive vertically moving air flow from a vent opening 26 in a floor28 and vertically through the system 10 as assisted by the fan/LANtrays. At the top of the rack housing 12, an apertured top panel 26(FIG. 1) is provided to permit venting of the vertically moving air flowfrom the system 10.

At the top portion of each bay 14, in the intermediate region betweenthe front bay portion 16 and the rear bay portion 18, as best seen inFIGS. 1, 5, 6 and 8, a power distribution unit (PDU) 29 is provided tosupply electricity to various components mounted in the rack mountedsystem. Each bay is adapted to accommodate a plurality of computercomponents in the form of open structure computer components or blades,such as blade 32 (FIG. 1), in each of the front bay portions 16 and therear bay portions 18. In the embodiment illustrated in the figures,eleven blades may be accommodated in each of the front bay and rear bayportions in a generally upright disposition. Thus, in the illustratedembodiment, the system 10 accommodates 66 computer components in adensely compact, closely spaced configuration.

The bottom control bay 21 is adapted to accommodate various controlcomponents. These control components may include a circuit breakerjunction box 34, as most clearly illustrated in FIG. 6. The circuitbreaker junction box 34 is electrically connected to each PDU. As shownin FIG. 4, a switch module 36 is also provided in the control bay 21.The switch module 36 is adapted to control communication between thevarious blades, such as blade 32, and a network, such as a local areanetwork, wide area network, or a public network, such as the internet.Further, the control bay 21 accommodates an air intake fan module 38(FIGS. 1 and 5) for facilitating intake of air through the bottomopening 25 and facilitating vertical air flow through the blades and thebays 14 and out the apertured top panel 26.

The embodiment of the rack system 10 illustrated in the figures includesfour casters 41 for rollably supporting the system on the floor 26 (FIG.5) for easy portability of the rack system 10. Other embodiments of therack system according to the present invention may be floor mounted,thereby including legs or skids in place of the casters for directmounting to the floor.

Fan/LAN Tray

Referring now to FIGS. 8 and 9, the fan/LAN tray 27 and its installationinto the rack housing 12 will be described in further detail. FIG. 9illustrates one embodiment of a fan/LAN tray 27 for use with the racksystem 10 illustrated in the drawings. The fan/LAN tray 27 includeseight suitable fans for facilitating vertical air flow. Although theembodiment illustrated in the drawings includes eight fans per tray, anysuitable number of fans may be used.

In accordance with the disclosed embodiments of the present invention,the fan tray may also be divided into a plurality of separate trays ortray portions, each of which can be removed independently so that theremaining tray portion can continue to function. In this regard, it iscontemplated that the LAN connections may be made in a unit or componentseparate from the fan tray or tray portions so that the tray or trayportion may be removed independently of the LAN component. In the frontportion of the fan/LAN tray 27, a series of LAN connector ports 45(FIGS. 1 and 9) is provided. In the embodiment illustrated in FIG. 9,each fan/LAN tray 27 includes 12 LAN connector ports 45, the end one ofwhich may be used for test purposes. While 12 LAN connectors are shownin the disclosed embodiment, it should be understood that any number ofsuch connectors may be employed for a given application. Internal wiringleads (not shown) from each LAN connector port 45 extend to one of twosignal connectors 47 (FIG. 9) in the back portion of the fan/LAN tray27. In one embodiment, each signal connector 47 is a 50 pin signalconnector, and is connected electrically to the switch module 36.Further, each fan/LAN tray includes a AC power inlet 49 in the backportion for providing power to the fans. When installed, power may besupplied to the fans 43 through the AC power inlet 49 from the PDU 29,as hereinafter described in greater detail.

For facilitating installation of the fan/LAN tray 27 into the fan/LANtray slot 23 of the rack housing 12, as shown in FIG. 9, guides 52 maybe provided on the sides of each fan/LAN tray 27. During theinstallation process, the guides, preferably nylon guides, may engagecorresponding member on the sides of the fan/LAN tray slots 23 to helpsupport the fan/LAN tray. Further, a locking mechanism may be providedin conjunction with the guides 52 for securing the fan/LAN tray 27 intothe fan/LAN tray slot 23 to help support the fan/LAN tray. Onceinstalled, each fan/LAN tray 27 occupies an area directly above eitherthe front bay portion 16 or the rear bay portion 18. Accordingly, afan/LAN tray in the front and a fan/LAN tray in the rear may completelycover each bay 14 level. Thus, as illustrated most clearly in FIG. 10, atotal of 6 fan/LAN trays 27, in addition to the air intake fan module 38may be provided in a three bay level rack mounted system 10 according toone embodiment of the present invention.

Computer Component Construction

Referring now to FIGS. 11, 25 and 26, the computer components or blades32 and their installation into the rack housing 12 will now be describedin greater detail. Each blade is provided with a pair of handles 54projecting from the front face of a front panel. The front panel extendstransversely to a rigid upright support or plate, and is connected tothe front edge of the support in an L-shaped configuration. The handlesallow a user to easily manipulate the blade 32 to be grasped by the userto slide the blade into or out of its bay. Each blade 32 may include oneor more mother boards 56. In the embodiment illustrated in FIGS. 25 and26, each blade 32 includes two mother boards 56 a, 56 b. Those skilledin the art will appreciate that the number of mother boards included ineach blade 32 may be varied according to design. The mother board mayinclude heat sinks such as heat sinks 58 and 59 for facilitating thecooling of the mother boards. Embodiments of the heat sinks aredisclosed in greater detail in U.S. Provisional 60/384,987, filed May31, 2002. Further, each mother board is provided with random accessmemory (RAM) 61. The amount of RAM 61 provided for each mother board maybe varied as needed. A pair of power supply 63 a, 63 b may be providedon the blade 32 for supplying power to their corresponding mother boards56 a, 56 b. Similarly, a pair of hard disks 64 a, 64 b may also beprovided on the blade 32.

All of the components are mounted on one side of the rigid plate orsupport 64, which is adapted to be supported vertically within its bay.Each blade 32 includes a cut-out corner portion or section 65 in itsupper back portion. The cut-out portion 65 is sized to receive andaccommodate the PDU 29 therebetween such that two opposing blades 32 and32 a (as shown in FIG. 26) accommodate the PDU 29 almost completely.Thus, a substantially zero footprint is achieved for the PDU 29. Eachblade 32 is provided with an AC power inlet such as an inlet 67 at ornear the cut-out portion 65. Thus, when the blade 32 is installed intothe rack housing 12, the AC power inlet 67 engages electrically acorresponding AC connector such as a connector 76 (FIG. 17) of the PDU29.

As most clearly illustrated in FIG. 11, the installation of the blade 32may be achieved in a fast and efficient manner. The blade 32 is simplyslid into either the front bay portion 16 or the rear bay portion 18 ofa bay 14 of the rack housing 12. Each blade 32 is slid back until its ACpower inlet 67 engages a corresponding AC connector 76 on the PDU 29.The intermediate dividers 19 serve as a back stop for the blades 32.Each blade 32 is secured in its slot by four blade screws 69, whichattach the blade 32 to the rack housing 12.

Once the blade 32 has been mounted onto the rack housing 12, a shortblade/LAN connector cable such as a cable 45 (FIG. 12) or a cable 71(FIG. 1) provides electrical networking connection between the blade 32and a network such as a local area network, wide area network or apublic network such as the internet. In this regard, the mother boardsare each mounted at the front of each blade, and thus access thereto isreadily available at front outlets such as at outlet 73 (FIG. 12). Thus,a data connection can be made from the outlet 73, through a short cable45, an inlet 77 of a PDU 29, which is coupled to the switch module 36.

Power Distribution Unit.

Referring now to FIGS. 17 through 20, the power distribution unit 29will now be described in greater detail. Power distribution unit 29supplies electrical power to the series of upright computer componentsor blades rack mounted side-by-side in a closely spaced configuration.As best seen in FIG. 26, each one of the blades such as the blades 32and 32 a have the cut out portion or section 65 in its upper backportion for receiving the PDU 29. In this regard, the cut out portions75 are complementary shaped relative to the cross sectional shape of thePDU 29. The PDU 29 is generally rectangular and cross sectioned, and thecut out corner portions 65 are generally L-shaped to compactly receivethe opposite sides of the PDU 29. Thus, the blades such as the blades 32and 32 a can be plugged into the PDU 29 in a very compact manner withoutthe necessity of having a back plane for receiving individual cables.The PDU 29 supplies power from an external power source, through thecircuit breaker junction box 34, to the various blades 32 and thefan/LAN trays 27. Each PDU 29 includes an elongated PDU body 74, whichpreferably is formed of a two piece, 18 gauge steel chassis. Each of twosides of the PDU body 74 includes a series of female AC connectors 76.In the embodiment illustrated in FIGS. 17 through 20, each side isprovided with 12 female AC electrical connectors 76. The twelveconnectors 76 correspond to eleven blades mounted in the front bayportion 16 and the rear bay portion 18 of each bay 14 and a fan/LAN tray27. The twelfth connector is for an AC power outlet on the front of thefan tray.

Thus, 12 female AC connectors 76 are provided on each of a front sideand a rear side of the PDU body 74. Each set of twelve female ACconnectors 76 receives power through a pair of power cables 72. In oneembodiment, the power cable 72 is a 15 amp power cable with strainedrelief near its junction with the PDU body 74. As described below, thepower cables 72 are routed to the circuit breaker junction box 34 in thecontrol bay 21. The PDU body 74 may also include a series of mountingstuds 78 for installation of the PDU body 74 to the rack housing 12.

Referring now to FIGS. 13 through 16, the routing of the various powerand LAN cables will now be described in detail. As illustrated mostclearly in FIG. 13, the power cables 72 from the PDU's 29 at each baylevel are directed along the right side of the rack housing 12 towardthe front portion of the rack housing 12 and to the bottom, where theyare connected electrically to the circuit breaker junction box 34. Thus,in the embodiment illustrated in the drawings, six power cables 72 areconnected to the circuit breaker junction box 34, since there are twofrom each one of the three PDUs. A set of three cables generallyindicated at 80 are each adapted to be coupled to a suitable source ofAC power to supply power to the system 10.

As also illustrated in FIG. 13, a set of six LAN cables 81 from thefan/LAN trays and PDUs are routed along the rear right side of the rackhousing 12 to the switch module 36. In the embodiment illustrated in thedrawings, two LAN cables 81 extend from each PDU which, in turn, areconnected electrically to a pair of fifty pin signal connectors 47.Thus, six such cables 81 are directed along the right side of the rackhousing 12. Similarly, as most clearly shown in FIG. 15, six LAN cables81 extend from the fan/LAN trays 27 and PDUs along the left front sideof the rack housing 12. These six cables 81 are also connected at theirlower ends to the switch module 36.

Once the rack system 10 is fully assembled with all the fan/LAN trays27, PDUs 29 and the blades 32 in place, a fully assembled and efficientrack mounted system is provided. In such a system, networking of thevarious components provided on the blades 32 is also performedefficiently. In the embodiment illustrated in the drawings, elevenblades are accommodated at each of the front bay portion 16 and the rearbay portion 18 at each bay 14. Thus, in the embodiment illustrated, 66such blades 32 may be accommodated. However, some of the slots may beoccupied by master computer components or blades such as the masterblades indicated at 32 a in FIGS. 4 and 6. In the illustratedembodiment, two master blades 32 a are provided in the bottom of thethree blade bays directly above the switch module 36. The master blades32 a are connected electrically directly to the switch module 36 viahigh speed connections (not shown) such as fiber optic connections. Themaster blades control the switch module 36 to switch communicationbetween the various slave blades 32 and the master blades. Accordingly,64 slave blades may be accommodated by the illustrated embodiment of thesystem. Each of the 64 slave blades may be hot swappable, for example,allowing replacement of the blades 32 without causing the shutting downof the system 10.

Each fan/LAN tray 27 is provided with twelve LAN connector ports such asthe port 45 (FIG. 1). Eleven of the 12 LAN connector ports 45 areadapted to permit communication between the various slave blades 32 andthe switch module 36. The twelfth LAN connector port 45 allows anexternal user to connect an external device such as a laptop computer tothe network. Further, each fan/LAN tray 27 is provided with a centrallydisposed AC power outlet for connecting such an external device.

According to the disclosed embodiments of the present invention, and asindicated diagrammatically in FIG. 21, the system 10 illustrated in thefigures provides efficient air flow to maintain a cool operatingtemperature for the various components mounted on the blades 32. Airflow is directed from the bottom opening 25 by the air intake fan module38 located in the control bay 21. The air intake fan module 38 directsthe air flow vertically through the various open structure blades 32 ateach bay level 14. The air flow is further facilitated by the fans 43 ineach fan/LAN tray 27 to move the air in its upwardly directed path oftravel. The air flow is directed out of the rack housing 12 through theapertured top panel 26.

FIGS. 21 through 24 illustrate further embodiments of the presentinvention. As illustrated in FIGS. 21 through 24, the intake and exhaustof the air flow may be varied to accommodate various configurations asto the availability of air supply in the immediate environment. Forexample, in FIG. 22, an air intake fan module 38 a draws air from abottom opening 25 a, similar to that illustrated in the embodiment shownin FIGS. 1 through 21. Air flow is directed vertically with the aid offans 43 a mounted on fan/LAN trays. However, unlike the previouslydescribed embodiment, in the embodiment illustrated in FIG. 22, the airflow is re-directed from a vertical path of travel at right angles to ahorizontal path of travel out of the rack system 10 a towards the rearof the rack housing. An air flow hood 85 a facilitates the rearwardre-direction of the air flow.

FIG. 23 illustrates yet another embodiment of the rack system accordingto the present invention. In this embodiment, an air intake fan module38 b draws air horizontally inwardly through an opening such as definedby a perforated plate 87 b in the bottom front portion of the rackhousing. The air flow is then re-directed upwardly with the aid of fans43 b mounted in fan/LAN trays. The air flow is directed vertically outof the top portion of rack system 10 b.

In the embodiment illustrated in FIG. 24, an air intake fan module 38 cdraws air horizontally through an opening such as defined by aperforated plate 87 c in the front bottom portion of the rack housing.The air flow is re-directed vertically through this system with the aidof fans 43 c. The air flow is re-directed at right angles to ahorizontal path of travel out of the rack housing rearwardly at the topof the rack housing. The rearward redirection of the air flow isfacilitated by an airflow hood 85 c. It will be appreciated by thoseskilled in the art that other variations on the intake and exhaust ofthe air flow are possible in accordance with other embodiments of thepresent invention.

While particular embodiments of the present invention have beendisclosed, it is to be understood that various different modificationsand combinations are possible and are contemplated within the truespirit and scope of the appended claims. There is no intention,therefore, of limitations to the exact abstract and disclosure hereinpresented.

What is claimed is:
 1. A power distribution unit for supplying power toa first and second back-to-back mounted series of upright computercomponents, each computer component having a single electrical connectorat its rear edge, comprising: an elongated body; a first series ofspaced apart connectors on one side of the body for electricallyinterconnecting with the connectors of the first series of computercomponents at the rear edges thereof; a second series of spaced apartconnectors on an opposite side of the body for interconnectingelectrically with the connectors of the second series of computercomponents; means for supplying electrical power to the body connectors;and wherein the back-to-back mounted computer components are disposedadjacent to one another and are powered by the single power distributionunit.
 2. A power distribution unit according to claim 1, furtherincluding: mounting studs for mounting said body in a transverse mannerrelative to said upright computer components to enable each one of thecomputer components to be connected electrically with said electricalconnectors.
 3. A power distribution unit according to claim 2, whereinsaid computer components each have a similar cut out portion, said bodyhaving a complementary cross sectional shape received by the cut-awayportions of the computer components to provide a compact mountingarrangement.
 4. A power distribution unit according to claim 3, whereinsaid means includes a second cable for supplying electrical power to theconnectors of the second series of computer components for energizingthe second set of blades.
 5. A power distribution unit according toclaim 3, wherein each one of said first and said second series ofcomputer components has a similar cut out portion, said body having acomplementary cross sectional shape received by the cut out portions ofthe second series of computer components to enable the first-mentionedand second series of computer components to be mounted back-to-back in acompact configuration.
 6. A power distribution unit according to claim5, wherein each cut out portion of the computer components is generallyL-shaped.
 7. A power distribution unit according to claim 6, whereinsaid body is generally rectangular in cross section, and wherein theL-shaped cut out portion of the opposing rear end portions of thecomputer components define a generally rectangular space for receivingthe body therewithin.
 8. A power distribution unit according to claim 2,wherein said means for supplying electric power includes a cable.